Associated Press
In this image taken from a Dec. 28, 2014 video and made available Wednesday, Dec. 31, 2014 passengers of the Italian-flagged ferry Norman Atlantic wait to be lifted from the deck by a rescue helicopter after it caught fire in the Adriatic Sea.

BRINDISI, Italy — Greece and Italy have issued widely different figures for how many people are still not accounted for in the ferry fire that killed at least 11 people in the Adriatic Sea.

The numbers ranged from as many as 98, according to Italian prosecutor Giuseppe Volpe, to 18, according to the Greek Merchant Marine Ministry. Greece says Italy's list is full of duplications and misspellings but the discrepancy could not be immediately explained since the prosecutor's office was closed for the New Year holiday.

A tug began towing the fire-ravaged ferry across wind-whipped seas toward Italy on Thursday afternoon. Giuseppe Barretta, owner of the tug boat company, told The Associated Press in the Adriatic port of Brindisi that the operation started near the coast of Albania, where the Norman Atlantic ferry had been stranded after Sunday's pre-dawn fire.

He estimated the towing could take 15 hours, depending on weather. Earlier, the Italian Coast Guard said waves in the region were as high as 5 meters (16 1/2 feet) and winds were blowing at more than 40 knots (46 mph).

Once the ferry arrives in Brindisi, Italian authorities will inspect its interior for any possible other bodies.

Cmdr. Floriana Segreto of the Italian Coast Guard said a total of 477 people were rescued from the stricken ferry. That figure, plus the 11 dead, would mean at least 488 people had been onboard as it sailed from Greece to Italy.

That's more than the 474 people who Greek officials said were officially on the ferry — leading to questions about Italy's tally or suggestions that the ferry also carried an unknown number of unregistered migrants.

Italy says it rescued or discovered some 170,000 migrants and asylum seekers at sea last year as they tried to slip into Europe.

D'Emilio reported from Rome.